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Ambient Heat and Sudden Infant Death: A Case-Crossover Study Spanning 30 Years in Montreal, Canada.

Auger N, Fraser WD, Smargiassi A, Kosatsky T - Environ. Health Perspect. (2015)

Bottom Line: The likelihood of sudden death increased steadily with higher temperature.Associations were stronger for infants 3-12 months of age than for infants 1-2 months of age, with odds ratios of 3.90 (95% CI: 1.87, 8.13) and 1.73 (95% CI: 0.80, 3.73), respectively, for 29°C compared with 20°C on the day of the event.High ambient temperature may be a novel risk factor for SIDS, especially at ≥ 3 months of age.

View Article: PubMed Central - PubMed

Affiliation: Institut national de santé publique du Québec, Montreal, Quebec, Canada.

ABSTRACT

Background: Climate change may lead to more severe and extreme heat waves in the future, but its potential impact on sudden infant death-a leading cause of infant mortality-is unclear.

Objectives: We sought to determine whether risk of sudden infant death syndrome (SIDS) is elevated during hot weather.

Methods: We undertook a case-crossover analysis of all sudden infant deaths during warm periods in metropolitan Montreal, Quebec, Canada, from 1981 through 2010. Our analysis included a total of 196 certified cases of SIDS, including 89 deaths at 1-2 months of age, and 94 at 3-12 months. We estimated associations between maximum outdoor temperatures and SIDS by comparing outdoor temperatures on the day of or day before a SIDS event with temperatures on control days during the same month, using cubic splines to model temperature and adjusting for relative humidity.

Results: Maximum daily temperatures of ≥ 29°C on the same day were associated with 2.78 times greater odds of sudden infant death relative to 20°C (95% CI: 1.64, 4.70). The likelihood of sudden death increased steadily with higher temperature. Associations were stronger for infants 3-12 months of age than for infants 1-2 months of age, with odds ratios of 3.90 (95% CI: 1.87, 8.13) and 1.73 (95% CI: 0.80, 3.73), respectively, for 29°C compared with 20°C on the day of the event.

Conclusions: High ambient temperature may be a novel risk factor for SIDS, especially at ≥ 3 months of age. Climate change and the higher temperatures that result may account for a potentially greater proportion of sudden infant deaths in the future.

No MeSH data available.


Related in: MedlinePlus

Association between maximum temperature and SIDS by postneonatal period, Montreal, April–October 1981–2010. Odds ratio (solid blue line) and 95% CIs (dashed outer bands). All temperatures are relative to the 20°C mark, and are adjusted for mean relative humidity. Associations for neonatal mortality were not computed because the number of cases was too low (n = 13).
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f2: Association between maximum temperature and SIDS by postneonatal period, Montreal, April–October 1981–2010. Odds ratio (solid blue line) and 95% CIs (dashed outer bands). All temperatures are relative to the 20°C mark, and are adjusted for mean relative humidity. Associations for neonatal mortality were not computed because the number of cases was too low (n = 13).

Mentions: When we ran spline models separately for the early and late postneonatal periods, the association between maximum temperature and SIDS was stronger for infants 3–12 months of age compared with those 1–2 months of age. Odds of SIDS in the 3–12 month postneonatal period were three to five times greater for temperatures ≥ 28°C relative to 20°C (Figure 2). This was the case for temperature both the day before and the day of death. Odds ratios at 30°C were 3.35 (95% CI: 1.33, 8.42) the day before and 5.03 (95% CI: 2.11, 11.96) the day of death compared with 20°C. In sensitivity analyses, restricting the analyses to SIDS from 3–6 months had no impact on the results (data not shown). The association with SIDS at 1–2 months was attenuated and statistically nonsignificant, although on the day of death the association was still positive with an odds ratio of 1.85 (95% CI: 0.78, 4.40) compared with an odds ratio of 1.12 (95% CI: 0.46, 2.74) the day before. Thus, the association between maximum temperature and SIDS both the day of and the day before was much stronger for SIDS at 3–12 months than at 1–2 months, suggesting that the findings for all ages combined were driven largely by cases that occurred at ≥ 3 months.


Ambient Heat and Sudden Infant Death: A Case-Crossover Study Spanning 30 Years in Montreal, Canada.

Auger N, Fraser WD, Smargiassi A, Kosatsky T - Environ. Health Perspect. (2015)

Association between maximum temperature and SIDS by postneonatal period, Montreal, April–October 1981–2010. Odds ratio (solid blue line) and 95% CIs (dashed outer bands). All temperatures are relative to the 20°C mark, and are adjusted for mean relative humidity. Associations for neonatal mortality were not computed because the number of cases was too low (n = 13).
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492261&req=5

f2: Association between maximum temperature and SIDS by postneonatal period, Montreal, April–October 1981–2010. Odds ratio (solid blue line) and 95% CIs (dashed outer bands). All temperatures are relative to the 20°C mark, and are adjusted for mean relative humidity. Associations for neonatal mortality were not computed because the number of cases was too low (n = 13).
Mentions: When we ran spline models separately for the early and late postneonatal periods, the association between maximum temperature and SIDS was stronger for infants 3–12 months of age compared with those 1–2 months of age. Odds of SIDS in the 3–12 month postneonatal period were three to five times greater for temperatures ≥ 28°C relative to 20°C (Figure 2). This was the case for temperature both the day before and the day of death. Odds ratios at 30°C were 3.35 (95% CI: 1.33, 8.42) the day before and 5.03 (95% CI: 2.11, 11.96) the day of death compared with 20°C. In sensitivity analyses, restricting the analyses to SIDS from 3–6 months had no impact on the results (data not shown). The association with SIDS at 1–2 months was attenuated and statistically nonsignificant, although on the day of death the association was still positive with an odds ratio of 1.85 (95% CI: 0.78, 4.40) compared with an odds ratio of 1.12 (95% CI: 0.46, 2.74) the day before. Thus, the association between maximum temperature and SIDS both the day of and the day before was much stronger for SIDS at 3–12 months than at 1–2 months, suggesting that the findings for all ages combined were driven largely by cases that occurred at ≥ 3 months.

Bottom Line: The likelihood of sudden death increased steadily with higher temperature.Associations were stronger for infants 3-12 months of age than for infants 1-2 months of age, with odds ratios of 3.90 (95% CI: 1.87, 8.13) and 1.73 (95% CI: 0.80, 3.73), respectively, for 29°C compared with 20°C on the day of the event.High ambient temperature may be a novel risk factor for SIDS, especially at ≥ 3 months of age.

View Article: PubMed Central - PubMed

Affiliation: Institut national de santé publique du Québec, Montreal, Quebec, Canada.

ABSTRACT

Background: Climate change may lead to more severe and extreme heat waves in the future, but its potential impact on sudden infant death-a leading cause of infant mortality-is unclear.

Objectives: We sought to determine whether risk of sudden infant death syndrome (SIDS) is elevated during hot weather.

Methods: We undertook a case-crossover analysis of all sudden infant deaths during warm periods in metropolitan Montreal, Quebec, Canada, from 1981 through 2010. Our analysis included a total of 196 certified cases of SIDS, including 89 deaths at 1-2 months of age, and 94 at 3-12 months. We estimated associations between maximum outdoor temperatures and SIDS by comparing outdoor temperatures on the day of or day before a SIDS event with temperatures on control days during the same month, using cubic splines to model temperature and adjusting for relative humidity.

Results: Maximum daily temperatures of ≥ 29°C on the same day were associated with 2.78 times greater odds of sudden infant death relative to 20°C (95% CI: 1.64, 4.70). The likelihood of sudden death increased steadily with higher temperature. Associations were stronger for infants 3-12 months of age than for infants 1-2 months of age, with odds ratios of 3.90 (95% CI: 1.87, 8.13) and 1.73 (95% CI: 0.80, 3.73), respectively, for 29°C compared with 20°C on the day of the event.

Conclusions: High ambient temperature may be a novel risk factor for SIDS, especially at ≥ 3 months of age. Climate change and the higher temperatures that result may account for a potentially greater proportion of sudden infant deaths in the future.

No MeSH data available.


Related in: MedlinePlus